U.S. Pat. No. 3,163,603 discloses amide and imide derivatives of metal salts of substituted succinic acids and illustrates the preparation of Zn, Mg, Ce, K, Li and Na salts of polyisobutenyl succinic anhydride (wherein the polyisobutenyl group is derived from a polymer of at least about 980 average molecular weight wherein small amounts (up to about 3 wt. %) of water was added in the reaction mass, based on the polyisobutenyl succinic anhydride charged.
U.S. Pat. No. No. 3,271,310, to LeSuer, discloses the production of certain metals salts of hydrocarbyl-substituted succinic acids and anhydrides and teaches that it is necessary to incorporate water in the reactants in an amount up to about 15% of the weight of the succinic compound if the hydrocarbyl-substituted succinic anhydride form is employed in the charge. Examples of the use of varying amounts of water (in amounts of zero up to about 20 wt. %, based on the polyisobutenyl succinic anhydride charged) are shown for preparing certain salts of Ba, Pb, Na, Ca, Ni, Cd, K, Zn, Li, Sn, Co and Al.
U.S. Pat. No. 3,652,616 discloses compositions for fuels and lubricants prepared by (a) reacting a hydrocarbon-substituted succinic anhydride and certain alkylene polyamines, and (b) reacting the resulting material with a metallic reactant. The patent teaches that it is sometimes necessary to use a co-solvent to solubilize the anhydride, polyamine and/or metallic material, and indicates that water, methyl or ethyl alcohol, THF, DMSO, diglime, cellosolve, dioxane or dimethyl formamide may be used as a co-solvent.
U.S. Pat. No. 4,552,677 to Hopkins is an indication of prior art processes, wherein a copper compound such as cupric acetate hydrate, basic cupric acetate, cuprous carbonate, basic cupric carbonate, and cuprous or cupric hydroxide is introduced into a reaction vessel containing a C.sub.8 to C.sub.35 hydrocarbyl-substituted succinic anhydride. The patent illustrates preparation of copper salts with water added to the reactants in an amount of up to about 100 wt. % in excess of the amount of water theoretically required to hydrolyze the C.sub.8 to C.sub.35 hydrocarbyl-substituted succinic anhydrides charged.
U.S. Pat. No. 4,751,011 discloses compositions comprising an interactive viscosity modifying polymer and a (Group I or II) metal salt of polyolefin-substituted dicarboxylic acid or anhydride and describes that the metal salt co-additive can be prepared by first dissolving polyisobutenyl-substituted dicarboxylic acid in mineral oil solvent and then introducing a metal acetate along with a moderate amount of water. The patent (Example 6) illustrates the preparation of Cu-PIBSA using about 110 wt. % excess water above the stoichiometric amount of water to hydrolyze the polyisobutenyl-substituted succinic anhydride charged.
European Pat. No. Publication 273,626 discloses a method for preparing Group I-B and II-B metal salts of polyolefinic-substituted dicarboxylic acid anhydride from a Group I-B or II-B metal reactant (e.g., CuO, ZnO, Cu(OH).sub.2, CuCO.sub.3 and the like), polyolefinic-substituted dicarboxylic acid anhydride and a short chain carboxylic acid (e.g., acetic acid), and discloses adding water to the reactor in an amount preferably from 1to 200 wt. % excess water above the stoichiometric amount required to hydrolyze the anhydride groups to facilitate reaction of the acid groups with the Group I-B or II-B metal reactant, in combination with copper oxide (a water insoluble metal compound), acetic acid and the polyolefinic-substituted dicarboxylic acid anhydride. The Examples employ water added in a 1,360 wt. % excess above the theoretical hydrolysis amount.
Co-pending Serial No. 306,117, filed Feb. 6, 1989, discloses the preparation of copper salts of polyisobutenyl succinic anhydride wherein water may be added to facilitate reaction with the anhydride material, and illustrates preparation of a series of copper products employing cupric acetate monohydrate, polyisobutenyl succinic anhydride and water added in amounts of from about 160 to 465 wt. % excess above the amount theoretically required to hydrolyze the anhydride material charged.